I finished a blender project, how do I export it with all the features?
You should first ask for which software you are exporting. It can be very different if you target 3d printing, VR or an animation short. 

Maybe your colleagues are using 3DS Max (there is a .3ds export) or Unity3D (you can use Blender files). However some features like particles for example might not be supported. You should be able to find workarounds (convert the particles to mesh: see here or create particles in the targeted software, Unity3D has a lot of options for example).